As far as I am aware iOS upgrades/updates bricking devices are rare and not commonplace, especially iPads.
Happens sometimes with iPhones, but kinda rare on iPad.
My iPad 2 is purring right along on iOS 9.3.5/
I never heard of an iPad logic board being "spoiled".
That description and solution from your Apple Store sounds fishy to me.
Is this store a real Apple Store location or an Apple reseller?
You know, you could call Apple directly at 1-800-MYAPPLE, ask for sales/customer service and take your iPad 2 issue up with Apple in Cupertino, CA directly.
Be calm and calmly explain to the Apple employee/representative what happened to your iPad 2. Maybe some sort of compromise can be reached.
If you have an issue with the solution from the first Apple representative, if you need to take your iPad 2 issue to another level Apple employee, again, calmly explain your iPad 2 issues, once again
You may still have to pay for a replacement model, but maybe it wont be $199 U.S.D.
Explain you did nothing, but try to upgrade the iOS over Wifi and it bricked your device.
Worth a shot!
BTW, did you ever try updating the iOS on this iPad 2 using the latest iTunes on a computer?
The BEST method is doing iOS upgrades/updates connected to a computer running the latest iTunes version.
I have been upgrading/updating iDevices for over 8 years and NEVER use the WiFi, over the air method.
There can be too many data transfer issues/errors that can get introduced if you don't have a good and stable wireless Internet connection as sometimes, as you have discovered, the over the air upgrade/update can introduce errors and CAN go wrong.
Wifi, over the air upgrades/updates from Apple only contain what Apple thinks, based on your connected device to their servers, what iOS upgrade/update pieces are needed for your iDevice. Sometimes, the selection can be error prone.
By using the iTunes from a computer method, you get the entire, full iOS upgrade/update and your iDevice will take in, via iTunes connection only what it can use, from the entire iOS upgrade/update ,on its own.
BTW,
You'll be worse off on Android as there are lots of mobile viruses and hacking of all Android devices and Google doesn't keep up with security updates.